Expose a lower bound of malloc'd memory via heap statistics

src/debug/debug-scopes.cc

Index: src/debug/debug-scopes.cc
diff --git a/src/debug/debug-scopes.cc b/src/debug/debug-scopes.cc
index 8e1c3a7a55935e85e2706274a4de215e92538f8f..3b0016fdfe35a633b9ad8fbcea6cc4c1115256bb 100644
--- a/src/debug/debug-scopes.cc
+++ b/src/debug/debug-scopes.cc
@@ -82,7 +82,7 @@ ScopeIterator::ScopeIterator(Isolate* isolate, FrameInspector* frame_inspector,
   // Reparse the code and analyze the scopes.
   Scope* scope = NULL;
   // Check whether we are in global, eval or function code.
-  Zone zone;
+  Zone zone(isolate->allocator());
   if (scope_info->scope_type() != FUNCTION_SCOPE) {
     // Global or eval code.
     Handle<Script> script(Script::cast(shared_info->script()));